When electrical motors are subject to constraints or to speed variations, they undergo heating, which must be controlled, so that their output remains as close as possible to an optimum efficiency. To that purpose, today's electric motors comprise generally a fan with rotary blades, which is mounted on the shaft of the motor and which communicates with the outside through a grid provided in the frame of this motor. In case of very large plants, more sophisticated air or water cooling systems may be used.
Nevertheless, all present solutions have the disadvantage that they cannot collect the calories in the heart of the motor and that they only ensure a more or less peripheral cooling of the frame. Therefore, the efficiency of the cooling remains low.
The patent application US 2005/120720, which describes a magnetocaloric generator intended for generating thermal power, is known. The thermal generator described in this application however does not relate to a motor and does not touch on the problem of the cooling of a motor.